Run time field generates error when trying tutorial

Elastic Stack Elasticsearch
,
1

I'm trying to learn how to create run time fields by following the instructions on this page:

I tried my own variation with these queries:

PUT rfield

POST rfield/_doc
{
  "Favourite Food": "My fave food is"
}

GET rfield/_search
{
  "runtime_mappings": {
    "new_field": {
      "type": "keyword",
      "script": {
        "source": "emit(doc['Favourite Food'].value + ' Pizza')"
      }
    }
  },
    "aggs":{
    "new_field": {
      "terms": {
      "field": "new_field"
      }
    }
  }
}

But my search query causes this error:

{
  "error": {
    "root_cause": [
      {
        "type": "script_exception",
        "reason": "runtime error",
        "script_stack": [
          "org.elasticsearch.server@8.7.0/org.elasticsearch.index.mapper.TextFieldMapper$TextFieldType.fielddataBuilder(TextFieldMapper.java:969)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.index.fielddata.IndexFieldDataService.getForField(IndexFieldDataService.java:102)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.index.query.SearchExecutionContext.lambda$setSourceProvider$3(SearchExecutionContext.java:513)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.SearchLookup.getForField(SearchLookup.java:115)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup$2.run(LeafDocLookup.java:153)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup$2.run(LeafDocLookup.java:132)",
          "java.base/java.security.AccessController.doPrivileged(AccessController.java:318)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup.getFactoryForDoc(LeafDocLookup.java:132)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup.get(LeafDocLookup.java:170)",
          "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup.get(LeafDocLookup.java:32)",
          "emit(doc['Favourite Food'].value + ' Pizza')",
          "         ^---- HERE"
        ],
        "script": "emit(doc['Favourite Food'].value + ' Pizza')",
        "lang": "painless",
        "position": {
          "offset": 9,
          "start": 0,
          "end": 44
        }
      }
    ],
    "type": "search_phase_execution_exception",
    "reason": "all shards failed",
    "phase": "query",
    "grouped": true,
    "failed_shards": [
      {
        "shard": 0,
        "index": "rfield",
        "node": "aIxuZp6uT8SfhHqfRZTJFg",
        "reason": {
          "type": "script_exception",
          "reason": "runtime error",
          "script_stack": [
            "org.elasticsearch.server@8.7.0/org.elasticsearch.index.mapper.TextFieldMapper$TextFieldType.fielddataBuilder(TextFieldMapper.java:969)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.index.fielddata.IndexFieldDataService.getForField(IndexFieldDataService.java:102)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.index.query.SearchExecutionContext.lambda$setSourceProvider$3(SearchExecutionContext.java:513)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.SearchLookup.getForField(SearchLookup.java:115)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup$2.run(LeafDocLookup.java:153)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup$2.run(LeafDocLookup.java:132)",
            "java.base/java.security.AccessController.doPrivileged(AccessController.java:318)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup.getFactoryForDoc(LeafDocLookup.java:132)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup.get(LeafDocLookup.java:170)",
            "org.elasticsearch.server@8.7.0/org.elasticsearch.search.lookup.LeafDocLookup.get(LeafDocLookup.java:32)",
            "emit(doc['Favourite Food'].value + ' Pizza')",
            "         ^---- HERE"
          ],
          "script": "emit(doc['Favourite Food'].value + ' Pizza')",
          "lang": "painless",
          "position": {
            "offset": 9,
            "start": 0,
            "end": 44
          },
          "caused_by": {
            "type": "illegal_argument_exception",
            "reason": "Fielddata is disabled on [Favourite Food] in [rfield]. Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [Favourite Food] in order to load field data by uninverting the inverted index. Note that this can use significant memory."
          }
        }
      }
    ]
  },
  "status": 400
}

What did I do wrong?

2

I solved the problem making sure I define a mapping first before I post the first record:

PUT rfield/_mapping
{
  "properties": {
    "Favourite Food": {"type":"keyword"}
  }
}
3

Yep, I was just about to write that but one other thing it's not a great idea or best practice to have spaces in your field names underscores are much better